One-step green synthesis of graphene/ZnO nanocomposites for non-enzymatic hydrogen peroxide sensing

Abstract

In the present study, a disposable electrochemical biosensor for hydrogen peroxide (H2O2) was fabricated using a graphene/ZnO nanocomposite-modified screen-printed carbon electrode (SPCE). The adopted method is simple, cost feasible and it avoids the usage of harsh oxidants/acids during the synthesis. Graphite material was subjected to liquid-phase exfoliation with the aid of ultrasonication, without going through the intermediate graphene-oxide phase that can disrupt the pristine structure of the yield. The as-prepared graphene/ZnO nanocomposite was then thoroughly characterized to evaluate its morphology, crystallinity, composition and product purity. All the results clearly indicate that pristine graphene was successfully produced with the graphite exfoliation and ZnO nanoparticles were homogeneously distributed on the graphene sheet, without any severe aggregation. The biosensing capability of the graphene/ZnO nanocomposite-modified SPCE was electrochemically evaluated with cyclic voltammetry (CV) and an amperometric analysis. The resulting electrode is found to exhibit an excellent electrocatalytic activity towards the reduction of H2O2. The graphene/ZnO-modified SPCE can detect H2O2 in a linear range of 1 mM to 15 mM with a correlation coefficient of 0.9859. The electrode is found to have a high sensitivity, selectivity and superior reproducibility for the non-enzymatic detection of an H2O2 compound. Keywords: graphene/ZnO nanocomposite, sonochemical facile synthesis, electrochemical sensor, screen-printed carbon electrode, hydrogen peroxide V predstavljeni {tudiji je bil izdelan elektrokemijski biosensor za enkratno uporabo za zaznavanje vodikovega peroksida (H2O2) z uporabo sitotiskane ogljikove elektrode (SPCE), modificirane z nanokompozitom grafen-ZnO. Ta prilagojena metoda je enostavna, stro{kovno ugodna in omogo~a, da se izognemo uporabi ostrih snovi, oksidanti-kislina, med sintezo. Grafitni material je bil izpostavljen ultrazvo~ni obdelavi, lu{~enju v teko~i fazi, ne da bi bil {el skozi vmesno fazo grafenovega oksida, ki lahko moti neokrnjeno zgradbo pridelka. Pripravljeni nanokompozit grafen-ZnO je bil nato skrbno karakteriziran, ocenjena je bila morfologija, kristalini~nost, sestava in tudi~istost proizvoda. Rezultati jasno ka`ejo, da je bil neokrnjen grafen izdelan z glajenjem grafita, ZnO nanodelci pa so bili homogeno razporejeni na plo{~ici iz grafena brez ve~jih segregacij. Biolo{ka ob~utljivost plo{~ice SPCE, modificirane z nanokompozitom grafen-ZnO, je bila ugotovljena elektrokemijsko s cikli~no voltametrijo (CV) in amperometri~no analizo. Ugotovljeno je bilo, da ima dobljena elektroda odli~no elektrokataliti~nost za redukcijo H2O2. SPCE, modificirana z grafen-ZnO, lahko zazna H2O2 v linearnem podro~ju od 1 mM do 15 mM s korelacijskim koeficientom 0,9859. Ugotovljeno je bilo, da ima elektroda veliko ob~utljivost, selektivnost in bolj{o ponovljivost pri neencimatski detekciji spojine H2O2. Klju~ne besede: nanokompozit grafen-ZnO, sonokemijska sinteza, elektrokemijski senzor, sitotiskarsko nat...

<i>Malus domestica</i> and <i>Solanum lycopersicum</i> Mixtures for the Synthesis of Graphene Silver and Zinc Oxide Nanocomposites

“…Li et al, 2013 [16] reported the use of green synthesized graphene|silver electroactive sensors for the detection of tryptophan. In a similar study, the one-step green synthesis of graphene|zinc nanocomposites for the nonenzymatic sensing of hydrogen peroxide is also reported [17].…”